Axion is an open-source Minecraft building toolkit built as a Fabric client mod with a companion Paper plugin for server-backed multiplayer editing.

Quick Links

• MOD-README — Fabric mod install and usage (for Modrinth)
• PLUGIN-README — Paper plugin install and server notes (for Modrinth)
• Wiki — Documentation, usage notes, and setup pages
• Contributing — Development guide for contributors

Changelog

v0.2.8 (Released)

• UI/UX Polish — Reworked the tool hint HUD into compact contextual prompts, including under-crosshair mouse hints and bottom-right keybind hints.
• New GUI Assets — Added texture-backed mouse/input hints and a new icon-based Axion tool palette.
• Alt Tool Menu Improvements — Holding Alt now expands the tool stack with cleaner icon slots and improved hover/selection behavior.
• Iris Shader Support — Added Iris shader-pack detection and shader-aware preview fallback so large previews behave correctly when shaders are enabled or toggled.
• Input Fixes — Improved mouse-scroll handling so Axion does not hijack scrolling while chat, menus, or option screens are open.
• Minecraft 1.21.2 - 1.21.3 Support — Added a single range jar compiled against Minecraft 1.21.3 for the 1.21.2 through 1.21.3 client and Paper plugin line.
• Release Automation Update — Release tags now publish the jars produced by ./build-axion.sh all to the GitHub release, with release body text loaded from .release/latest/<tag>.md.
• Supported Versions — Axion v0.2.8 supports Minecraft 1.21.2 through 1.21.11 and 26.1.x.

v0.2.7 (Released)

• Minecraft 26.1.x Support — Fabric client compatibility work for the latest Minecraft version
• 26.1.x Rendering Fixes — Restored toolbox icon textures, selection visuals, move-source glass overlays, and GPU block previews
• Smear Tool Overhaul — True block smearing that samples your selection and spreads blocks as you scroll, perfect for creating staircases and roofs
• Stack & Smear Reliability — Increased repeat limits, improved large GPU previews, fixed no-op smear feedback, and made smear overlap resolution more deterministic
• Hotbar Save/Load Fixes — Saved hotbars restore correctly on 26.1.x
• Paper Admin Reload — Added console-only /axion reload for reloading Paper plugin config and policy options without restarting the server
• Magic Selection Enhancements
  • More block tags available for custom masks
  • Red outline for disabled templates for easy visual identification
  • Same Block Select toggle to pick up matching blocks outside your mask
  • Continuous stroke support for faster large selections
• 1.21.5 - 1.21.8 GPU Preview Compatibility
  • Added chunked GPU preview support for Minecraft 1.21.5
  • Added chunked GPU preview support for the legacy 1.21.6 - 1.21.8 range, compiled against 1.21.7
  • Large move, clone, stack, smear, and glass/origin overlay previews now use persistent per-section GPU buffers on these older ranges
  • Modern 1.21.9 - 1.21.11 previews adapt at runtime across the render-pass texture binding and DynamicUniforms API changes in that range

Next: v0.2.9

• 26.1.x Fabric Dedicated Server Support — Fabric dedicated server support for the 26.1.x range is planned next in v0.2.9.
• 1.21.1 Support — Minecraft 1.21.1 remains the next 1.21.x client and Paper plugin backport target.

Roadmap & Upcoming

Future Plans

• More "capabilities" like No Updates, Phantom, Angel Placement and Tinker
• Add support for older Minecraft versions after the 1.21.x backport work
• Add support for more Minecraft versions on Fabric dedicated servers
• UI improvements and polish
• 0.3.0 and beyond: Develop the Editor Mode for more advanced building workflows (MCEdit-style editor)

Support

• Issues: https://github.com/castledking/Axion/issues
• Wiki: https://github.com/castledking/Axion/wiki
• Discord: https://discord.com/invite/pCKdCX6nYr
• Website: https://castled.codes